PRESSURE-COMPENSATED MICRO FLOW CONTROL VALVE

摘要

PROBLEM TO BE SOLVED: To provide a pressure compensated flow valve for solving the nonconformity that the correct time from mixing with a probe gas to detection cannot be grasped due to stagnation inside the valve, in the case of using prior art of a leakage valve with regard to the pressure compensated micro flow valve of CVD device or the like for form of thin membrane, especially, in the development of technical skill of detection for leakage by means of probe gas method. SOLUTION: There is provided with the region of opening and closing mechanism which comprises a valve body 7 in fluid communication with a flow passage within a duct and a port of leakage 92 and axially disposing a valve duct 3 which enables the upper end to project into the flow duct within the duct; a valve housing 8, fixed above the valve body and a capable of raising and lowering a valve rod 6 in the bore in the axial direction; a needle 2 inserted into a hole suspending from lower end of the valve rod and forming clearance, capable of flowing a small amount of water between the valve duct and the needle; a valve seat 4 on upper end of the valve duct; and packing; and which is provided with the region of the flow control by closely making the flow passage within the duct in closing position or by opening the flow passage within the duct.